Rim grip brake



Oct. 24, 1950 R. B. POGUE 2,527,072

I RIM GRIP BRAKE Filed June 3, 1946 3 Sheets-Sheet 1 Oct. 24, 1950vPOGUE 2,527,072

RIM GRIP BRAKE Filed June 3, 1946 3 Sheets-Sheet 2 RtB. POGUE 2,527,072

RIM GRIP BRAKE Oct". 24, 1950 Filed June 3, 1946 3 Sheets-Sheet 3Patented Oct. 24, 1950 UNITED: STATES PATENT OFFICE RIM GRIP BRAKERobert B. Rogue, West Orange, N. J., assignor to,

American Brake Shoe Company, New York, N. Y1, a corporation of DelawareApplication-June 3, 1946, Serial No. 673,923-- 9 Claims. 1 i

This invention relates to brakingapparatus and more particularly toapparatusofthis character embodying a disc toat least one face of whichone or more brakingelements are applied to effectdecelerationof thediscand apparatu with which ,it is connected. In. those instancesheretofore where at least one braking element. has been appliedto atleast one face of adisc to effect deceleration thereof andapparatus withwhich the disc is connected, it has been necessary to accurately applyforce to sucha. brakingelement so as toinsure flat and even seating ofthe-operative face. thereof against the face of the disc with whichit isto be used. Otherwise experience has shown that the operative face ofthe braking elements will wear unevenly. This, of course; ishighlyobjectionable since uneven wear of the operative face of brakingelements of this character: makes it necessary to discard the brakingelement prior to the time the anticipated life thereofhadbeen realized.The foregoing has been particularly true in those instances wherecomposition friction material'has beenprovidedon the operative face of abraking element-of the aforesaid char,- acter, for in such instances ithas been customary to back up such friction material with a metallicreinforcing element. In those instances where the composition frictionmaterial wears unevenly the adjacent face of the metallic backingelement is approached much more rapidly than this would occur if. thefriction material should wear away evenly. In this respect, in. thoseinstances where composition friction material is employed in theaforesaid manner, it is desirable to avoid wearing away the compositionfriction material completely at any point; so as to expose -the metallicrein.- forcingbacking inasmuch as contact of the metallic reinforcingbacking with. the face of the disc might ofttimes result in scoring or.other damaging of the disc.

It is therefore the primary object of my invention to insure that theoperative face of a braking element will beapplied/to the face of-adisc,

2, thereto. In such instances. the braking elementsv have been ofarcuate configuration so as to be complementary, to braking. surfacesafforded on opposite faces of the disc, and usually such brakingelements have been appliedto but a portion, of suchv brakingv surfaces.In arrangements of this character. ithas been customary to support thebraking elements atfcorresponding ends of lever arms. that have beenfulcrumed in. such a way that when pressure is applied to. ends of the.lever arms opposite those whereat the braking, elements are supportedsuch elements are forced into engagement with braking surfaces onopposite sides of a disc. In many such instances in the past the brakingelements have been, piv.- otally connected to the lever arms andinssuch. circumstances it has been necessarytoaccurately relate thepivotal mounting of the braking 619-.- ment to the, operative face ofthe element asto thereby insure flat andv even application of. suchoperative face of the. element to the braking surface with which it isadapted to cooper ate to effect deceleration of the disc and apparatusconnected thereto. Since. it is customary in such circumstances toarrange for the removalof one such braking element and the replacementthereof by another such element, it has been necessary heretoforetoaccurately manufacture the various elements so as to insure thedesired relation between the pivotal mounting and the operative face ofsuch an element. This has usually contributed to a substantial increasein manufacturing costs of such elements and in practice has not beenfully satisfactory, even at increased cost. It is, therefore, yetanother. object of this invention to so arrange a braking. element oftheaforesaid character and the. pivotal mounting thereof in such a mannerthat a, highly accurate relationship need. notbe estab-. lished betweenthe pivotal mounting of such ,an elementand the operative face thereof.Objects related to the foregoing are to insure that the operative faceof a braking element of, the aforesaid character will be properlyengaged with the braking surface on a disc with which it is adapted tocooperate, and to insure that the operative face of a braking element ofthe aforesaid character will cooperate with'a braking surface on theside of a disc in such a way as not to promote uneven-wear of theoperative face of such element.

the @LfOISaid Character that will be effective to guide the operativeface of such a braking element into proper relation with a brakingsurface on the side of a disc and to insure against binding of suchguide means so as to thereby insure that such guide means will notprevent proper cooperation between the operative face of a brakingelement and the braking surface with which it is to be engaged.

In those instances where braking elements are pivotally connected tolever arms in the above described manner so as to be arranged in atleast substantially opposed relation to thereby cooperate with brakingsurfaces on opposite faces of a disc, it is a yet further object of thisinvention to so interrelate the braking elements'that the operativefaces thereof will be mutually guided into proper cooperation with thebraking surfaces with which they are respectively adapted to cooperate.Objects ancillary to the foregoing are to afford a guiding device oneach of such elements and to extend the guiding device on one suchelement into operative relation with the other element to therebyinterrelate the elements and insure proper positioning thereof with thebraking surfaces with which such elements are respectively adapted tocooperate and to so arrange such guiding devices as to prevent suchbinding thereof as might be effective to prevent proper functioning ofthe braking elements.

Other and further objects of the present invention will be apparent fromthe following description and claims and are illustrated in theaccompanying drawings which, by way of illustration, show preferredembodiments and the principles thereof and what I now consider to be thebest mode in which I have contemplated applying those principles. Otherembodiments of the invention embodying the same or equivalent principlesmay be used and structural changes may be made as desired by thoseskilled in the art without departing from the present invention and thepurview of the appended claims.

In the drawings,

Fig. 1 is a perspective view of a disc brake arrangement embodying oneform of my invention;

Fig. 2 is an end elevational view of one of the braking elements shownin Fig. 1 and also showing the interrelation between such element andthe guiding device on the other element of a disc brake arrangement;

Fig. 3 is a fragmentary perspective view of a disc brake arrangementembodying another form of my invention;

Fig. 4 is a fragmentary elevational view looking at the right-hand sideof the braking arrangement as shown in Fig. 3;

Fig. 5 is an elevational view of the braking arrangement shown in Fig. 3looking in a direction perpendicular to that of Fig. 4;

Fig. 6 is a vertical sectional view taken substantially on the line 35on Fig. 4; and

Fig. 7 is a view somewhat similar to Fig. 6 but taken on the line 'I1,Fig. 4, and showing certain parts in a different operative positionthereof from the position shown in Fig. 6.

One embodiment of my invention is shown in Figs. 1 and 2 of thedrawings. Fig. 1 shows a brake disc element II, mounted for rotation ona supporting shaft to which it is non-rotatably secured in any desiredmanner. The shaft I 2 may be mounted in supporting frame elements I5 andI6 which, if desired, may be merely mountings for the bearings or theymay comprise housing elements for parts, not shown, associated with theshaft I2.

This invention is particularly adapted to heavy duty service and theshaft I2 may be, for example, an axle of a railroad car, tender orlocomotive, or it may be the axle, or a hub member, of an automotivetruck, or a shaft in a machine which requires periodic and effectivebraking. In railway applications, the braking apparatus to be describedhereinbelow may be applied, if desired, directly to the face or faces ofa car or locomotive wheel which wheel would then constitute the brakingdisc I I. Such an arrangement is shown broadly in the patent to TrainerNo. 2,352,223, patented June 27, 1944. As shown herein, however, thedisc is specially designed for braking, being provided with cooling finsIT for dissipating heat generated by braking friction to the atmosphere.If desired, the disc might be provided with other types of coolingelements, such as means for circulating a fluid therethrough or externalmeans for applying a coolant thereto may be provided as disclosed in myPatent No. 2,378,100 patented June 10, 1945.

The brake disc II, as shown herein and preferably as used in connectionwith the braking elements to be described hereinbelow, is provided withopposed braking faces I8 and I9 which are substantially parallel to eachother and each of which is of a character and material adapted tocooperate effectively with a friction brake shoe.

A brakeoperating mechanism, indicated generally at 2 I, is shown abovethe disc II in Fig. 1. This mechanism comprises a housing 22 for a setof bralreoperating elements which may be of any suitable character butare preferably of the hydraulic type. The housing 22 is secured to asuitable rigid support or frame member, not shown, by means such asstuds or bolts 23. Hydraulic connections are indicated at 24 and 25.These connections lead to a suitable source of hydraulic pressure, suchas a pump or a piston, not shown.

A pair of pivot pins or bolts 26 and 21 are mounted in the lower part ofthe housing 2| to support a pair of hangers 28 and 29, respectively.These hangers are each adapted to carry a brake shoe, that carried byhanger 28 being shown at 3| and that carried by hanger 29 being shown at32. Thesehangers are so pivoted and the shoes are so mounted thereon asto permit movement of the shoes toward and away from braking engagementwith a face I8 or I9 of the brake disc. Each of the brake shoes 3| or 32comprises a friction element 33 in the form of a block of suitablefriction material, carried by a backing or body member 34. Each backingmember is provided with cars 35 adapted to be pivotally connected to thelower end of an aforesaid hanger or arm 28 or 29 by means such as a pinor bolt 36. It will be understood that the upper ends of arms or hangers28 and 29 extend beyond the pivot pins 26 and 2! and are connected tooperating means such as hydraulic plungers or the like adapted to movethe arms simultaneously about the pivot pins 26, 21 so as to move bothshoes into or out of braking engagement with the disc or wheel I I.

It has been found in practice that although the supportinglugs 35 foreach of the brake shoes are located centrally of the shoe so as to applythe friction elements 33 with substantially uniform pressure over theirfaces during braking, nevertheless the friction elements tend to wearunequally unless some means are provided to prevent such wear. This isdue in part to the tangential'forces applied by the-rotatingdisc to thefriction element and is due in part to other causessuch as variations inresistance to wear of the friction, block, vibration, misalignment, etc.The uneven wear which results-makes it necessaryto-replace brake blocks,,or atleastthe friction elements thereof much more frequently than wouldbe. necessary if the wear were even. Accordingly, thisinvention-contemplates the pro.- vision of guide means for each of thebrake shoes which guide means are effective to maintain proper alignmentand to causethe frictionelements to engage the disc faces squarely sosasto wear evenly. These means will next be described.

'The brake shoe 3!, as previously noted, comprises. a backing plate orbody member 34 which supports the friction element and also bears theshoe supporting ears 35. As shown in. Figs. 1 and 2,,aguide member M isattached to the body member 34 by means such as a stud 42. This guidemember comprises a rigid vertical: block or plate 43 which is firmlyattached to the member .34- and a horizontal arm 44 extending from the.block or plate 43 across the periphery of the disc to and across the topof the. opposing'brake shoe 32. The arm 44 is preferably integral. withthe block or plate 43. Y

On the opposing shoe 32 a generallysimilar guide member 45 ismounted insimilar fashion to the body member 34. The guide member consists of avertical block or rigid plate 45, secured to the outer vertical face ofthe body member 34. as bya stud identical with stud 42, and a horizontalarm 4-! extending across the periphery of the disc and to and across thebrake shoe 3!.

Each of the horizontal armsextends as acantilever across the block orplate which is integral with the other arm. Each of these block or platemembers 43 and 46 has a substantially horizontal guide surface rigidlyrelated thereto, and on which the arm from the opposing shoe may restfor sliding movement thereover as the brake shoes are applied to orreleased from the disc faces. formed thereon for cooperation with thearm-44,

while a similar surface 48 is formed adjacent to the block 43- on theedge. of the plate 34. In ad dition, each block or plate 43 and 46 has asub stantially vertical shoulder BI and 52, respec-- tively, againstwhich the side of the arm 41 or 44, respectively, may abut to preventtilting. or

twisting of the brake shoe out of parallelism with the friction blockwear more rapidly than the lower part, because the lever arms 44 and 41keep the shoes in general alignment. The shoes are permitted, however,to make minor self-ad justments, and the guide bars may slide freelyover opposing guide surfaces without. any binding action since they arefree to rise against thevertical shoulder, or to swing away from it somewhat, if the direction of brake application happens not tov be strictlyparallel to the. axis of the disc. Since there is some vibration intheshoes as the brakes are applied, this freedom of movement i desirablein certain constructions topre Thus the block 45 has a surface 49- ventbindingof the sliding parts" which might interfere with theapplicationxof the brakes and more particularly with their release;

Figs. 3 to 7 show another form of my invention where the guide means arerestricted against vertical movement, certain freedom of movement,being. allowed in a horizontal plane only. As shown in Fig. 3, the rightbrake shoe I3I bears a guide member I4'I comprising a block I43 rigidlysecured to the backing member I34 by studs or bolts I42. The block I43has an integral lever I44 extending as a cantilever across theperiphery, of the disc II and engaging a guide notch in-the-opposingblock I46 which comprises part of the opposite guide member I45. Theblock I46 carries an integral lever I41 which extends-across-the discperiphery to a guide notch in the first block I43. The guidingnotch orslot inblock I43 is shown at I48 and that in the other block. I45 isindicated at I49, Figs. 3, 4.

It shouldbe particular-1y noted that the guide notches I48 and l iare-slightly larger in a vertical direction than the correspondingdimension of the guide lever or bar I44 or I41 which they receive.This-construction is necessary to prevent binding as brakes are appliedand released. Necessary manufacturing tolerances and wear in other partssuch as the ears 35, the links 28, pivot pins 26- and- '21,;and thebrake .discand brake shoes themselves requirethat a certainfreedom ofmovement be permitted in the guide elements to avoid binding. Suchbinding would interfereparticularlywith release of the brakes aftertheir application. Experiments have shown that sufficient freedom of.movement. may be permittedin the guide elements I44 and I49, and I4! andI43, respectively, that binding is avoided without permitting materialmisalignment, or unevenapplicationof the brakeshoes. I

An extreme condition of misalignment is represented in the contrast.between Figs. -6 and 7. In Fig. 6, the center line of the pivots 26 and21, on which hangers 28-and 29 are mounted, is indicated by the lineA.A. The center line of thedisc, which is the center linebetween thebrake: shoes 3! and 32 is indicated at BB. As shown in Fig. 6, thesecenter lines are in alignment which is a desirable normal operatingcondition. However, in Fig. 7, corresponding lines A".A' and B.B, areshown considerably out of align-v ment, to an exaggerated degree,butrepresenta tive of conditions which may possibly be realizedin practice.Uneven wear of the disc or the bearings which support the shaft whichmounts it,

. wearin of -one of the brake shoes to a much greater-degree than theother, and misalignment of the brake operating mechanism with respect tothe disc andshoes, all might contribute to produce the conditionindicated in Fig- '7. In this case the shoes will be applied with aslight degree of inequality, but with the guiding means I44 and I49(Fig. 6), and guiding means I4I' and I48 (Fig. 7 serious misalignment ofthe brake shoes to the faces. of the disc is prevented, even with theextreme conditions of misalignment between the disc and the brakeoperating means indicatedin Fig. '7. q

It will of course be-understood that the heights of guide slots MG andI49, although somewhat greater than. the heights of the guide bars- I41and long so that considerable freedom of movement,

may be permitted in the guide slot with only very minor variationin thebrake blocks from a condition of true parallelism with the brakingsurfaces of the disc I I.

It will be understood that the modification of my invention described inconnection with Figs. 1 and 2 of the drawings differs from thatdescribed in connection with Figs. 3 to 7 only in that the firstmodification leaves the guide bars or levers free to swing upwardlywhereas in the second modification the bars are limited in such upwardmovement. For many uses the former will be found satisfactory since thenormal tendency is for the brake shoes to Wear more rapidly at the outerperiphery of the disc where velocity is greatest and this tends to tiltthe shoes inwardly at the top portions thereof. Such tilting isprevented just as effectively by the first modification, as shown inFigs. 1 and 2, as in the sec-- ond modification, and freedom frombinding is obviously superior. However, in other applications, it willbe found desirable or necessary to prevent the shoes from wearingunevenly at their lower or inner portions in which case the notchedguides I48 and I49, Figs. 3 to 7, will be found to be superior.

In both forms of my invention, the brake shoes are applied evenly andsmoothly, and the friction blocks 33 thereof may be almost entirelyconsumed before the backing or body members 34 begin to be exposed andreplacement becomes necessary. By thus insuring even and uniform wearreplacement of brake shoes (or of friction elements thereon) is notrequired as often as would otherwise be required and this results inconsiderable economy. In addition, braking is more efficient andeffective and scoring of the disc itself is avoided.

While I have disclosed the application of a pair of opposed brake shoesto a single disc, it will be understood that a single shoe or multipleshoes could be applied to only one face of a disc,

or that various combinations of brake shoes might be used with variousarrangements of discs. Further, it will be understood that theparticular forms of guiding elements may be varied to meet requirementand that clearances and tolerances to avoid binding will be adjustedaccording to the particular needs of the installation. The guideelements should be as free as may be permitted without allowingobjectionable misalignment or uneven application between the brake shoesand the braking surfaces of the disc. On the other hand, requirementsfor true alignment of the brake elements may be met as closely asoperating clearances to avoid binding between the guide elements willpermit. The use of relatively long guide levers as compared withdimensions of other parts of the brake shoes tends to minimizeinequalities or misalignments in braking,

Hence, while I have illustrated and described the preferred embodimentsof my invention, it is to be understood that these are capable ofvariation and modification and I therefore do not wish to be limited tothe precise-details set forth, but desire to avail myself of suchchanges and alterations as fall within the purview of the followingclaims:

I claimz 1. A brake mechanism comprising a pair of brake shoes adaptedto cooperate with opposed faces of a disc for braking action, a hangerfor each of said shoes, operating means for moving said shoes towardeach other for said braking action, a guide element on each shoe, and aguide bar extending from each brake shoe to the guiding element on theopposed shoe for maintaining said shoes in proper alignment during saidmovement. 7

2. A brake mechanism comprising a member having opposed braking surfacesand mounted for rotation with mechanism to be controlled by brakingaction, a pair of brake shoes each of which is adapted to cooperate withone of said surfaces, a hanger for each of said shoes, an operatingdevice for moving said shoes toward each other and against said surfacefor braking action, a receiving guide carried by each of said shoes, anda guide bar on each of said shoes extending to the receiving guide onthe opposed shoe.

3. A brake mechanism comprising a rotatable member having opposedbraking surfaces, a pair of movable brake shoes each of which is adaptedto cooperate with one of said surfaces, means for moving said shoes toand from braking cooperation with said surfaces, and means for guidingsaid shoes during such movement, said means comprising a bar guide oneach shoe and arprojecting bar extending from each shoe into said guideon the opposed shoe to maintain both shoes in proper alignment.

4. In a braking mechanism the combination of a rotating member having apair of substantially plane braking surfaces, a pair of brake shoes eachbearing a friction element and each adapted to be moved into frictionalengagement with one of said surfaces, a rigid block attached to each ofsaid shoes and provided with a guiding surface, and a guide arm carriedby said block and extending therefrom, the guiding surface on each ofsaid blocks being adapted to receive and guide the guide arm extendingfrom the block on the opposing brake shoe.

5. In combination, a brake mechanism com prising a rotatable brake dischaving substantially plane and parallel opposed braking faces, a pair ofbrake shoes each mounted for braking cooperation with one of said faces,and means for actuating said shoes substantially simultaneously, each ofsaid shoes comprising a body member, a friction element, and guide meansfor guiding said friction element squarely and evenly into brakingengagement with a braking face of said disc, said guide means comprisinga block secured to said body member and provided with a projecting guideelement and a receiving guide element for the projecting guide elementon the opposing brake shoe.

6. In combination, a brake mechanism comprising a rotatable brake dischaving substantially plane and parallel opposed braking faces, a pair ofbrake shoes each mounted for braking cooperation with one of said faces,and means for actuating said shoes substantially simultaneously, each ofsaid shoes comprising a body member, a friction element, and guide meansfor guiding said friction element squarely and evenly into brakingengagement with a braking face of said disc, said guide means comprisinga block secured to said body member and provided with a projecting guidebar and a receiving guide notch of size and shape to freely receive andguide the projecting guide bar on the opposing brake shoe.

7. In combination, a brake mechanism comprising a rotatable brake dischaving substantially plane and parallel opposed braking faces, a pair ofbrake shoes each of which is mounted for braking cooperation with one ofsaid faces, and

means for actuating said shoes substantially simultaneously, each ofsaid shoes comprising a body member, a friction element, and guide meansfor guiding said friction element squarely and evenly into brakingengagement with a face of said disc, said guide means comprising a blocksecured to said body member and provided with a rectangular,horizontally projecting guide bar extending to a similar block on theopposed brake shoe, and a rectangular receiving guide on said block of asize and shape to freely receive and guide the projecting guide bar onthe opposing brake shoe.

8, In braking apparatus for railway and like equipment, a mountingmember for carrying a replaceable friction element on one face of saidmember, means on said mounting member adapted to support such mountingmember on the brake-applying mechanism of a disk-type friction brakemechanism for braking application of a friction element carried by suchmounting member to one side surface of the brake-disk of such a frictionbrake mechanism, and a guide member secured on the other face of saidmember and having a rigid guide arm extended there- 25 from across oneedge of said member and beyond said one face thereof in perpendicularrelation to said one face, said guide member having at least one guidesurface located adjacent said other face of said mounting member andspaced laterally from and parallel to said guide arm and adapted, inuse, to be engaged by a similar guide arm of another mounting member.

9. In a brake arrangement, a rotor, stators at opposite sides of saidrotor adapted for braking engagement therewith, actuating meanspivotally connected to said stators, and guide means for controllingpivotal movement of said stators, said guide means comprising a pair ofguide elements, one fixed to each stator, each element comprising an armextending transversely of said rotor and a guide portion disposed at oneside of said rotor, the arm of each element engaging the guide portionof the other element.

ROBERT B. POGUE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,228,818 Eksergian Jan. 14, 19412,383,375 Eksergian et al. Aug. 21, 1945 2,423,694 Eksergian et al July8, 1947

